There is known a vehicle stabilizer system for reducing roll of a vehicle body, by utilizing a stabilizing force that is dependent on a torsional reaction of a stabilizer bar. In recent years, as disclosed in JP-2002-518245A (publication of unexamined Japanese Patent Application laid open in 2002) and JP-2004-314947A (publication of unexamined Japanese Patent Application laid open in 2004), there has been proposed a stabilizer system equipped with an actuator so as to be capable of changing the stabilizing force. Such a stabilizer system (hereinafter referred to as “active stabilizer system” where appropriate) has been already put to practical use.
A suspension device installed in a vehicle is arranged to cause toe and camber angles of a wheel of the vehicle to be changed in response to a vertical displacement of the wheel relative to a body of the vehicle. It is common that the vehicle is designed such that the vehicle has an understeer tendency as its cornering characteristic as a result of the change in the toe and camber angles of the wheel. There may be a case where the active stabilizer system is used with a suspension device that is designed for its use with a traditional stabilizer system not equipped with an actuator (hereinafter referred to as “conventional passive stabilizer system” where appropriate) rather than with the active stabilizer system. In such a case, since the active stabilizer system is capable of more effectively restraining or reducing roll of the vehicle body than the conventional passive stabilizer system, the change in the toe and camber angles of the wheel is somewhat restrained thereby possibly making it impossible to obtain a desired cornering characteristic of the vehicle. This is merely one example of problems encountered in the active stabilizer system. That is, in the active stabilizer, there is still room for improvement increasing its practical value.